Mixing drum gate



March 5, 1935. A. E, MASON MIXING DRUM GATE Filed Feb. 24, 1931 lnk 7 INI/EN TOR. ALF/PED E. Aso/V BY A TTORNE YS.

Patented Mar. 5, 1935 MIXING DRUM GATE v Alfred E. ,'Mason, San Francisco, Calif., assignor to Norris K; Davis, Inc., San a corporation of Nevada Francisco, Calif., n

Application February'zi, msn-serial 517,7434

7 Claims. (C1. 22o-47) end by a collarl 18 andiheldin place bya pin 19 passing through member 8. .This threaded bar` This' invention relates tol cylindrical 'concrete mixers-particularly of the type inwhich the drum revolves, and the objects Vof the invention are to provide an improved discharge closure at one end 4zi; of the drum, as well as cooperating mixing and discharge blades withinthe drum so that the load of mixed concrete may be dischargedwithout tilting the drum.

In the drawing accompanying this specification Fig. 1 is a vertical cross section of my discharge closure together with portion of the discharge blades and end wall of a concrete mixer drum.,

- Fig. 2 is a perspective View of a portion of a cylindrical concrete drum with alportion ofl the front wall broken away to show the internal arrangement of the mixer and discharge blades.

The drum may be any of a variety of forms as used in concrete mixers, for illustrative purposes being here shown as a horizontal cylinder're-:-

' volvable cylinder 1 of which the discharge end is designated 2 having an axially arranged circular discharge opening fitting with an angularly and outwardly extending annular flange 3 to guide discharging material from bespattering the outer end of the drum.

Positioned within the drum and secured to the head or end wall 2 of the same as by welding along the edge 4 are spirally curved and relatively wide blades 5 which together form funnel-like walls seated with the large end against the head 2 of the drum. The outer ends 5 of these blades are welded or otherwise secured to the wall of the cylinder 1 as by welding along the line 6, while the opposite ends 5" of the blades are curled inwardly and slanted relatively close together, the extreme outer corners of the inner ends of the blades are secured at '7 to an axially disposed tubular member 8 which is thereby held in position, while the other end of the tubular member is held centrally by means of a steel spider 9 preferably welded in place and at the outer ends of its arms at 10 to blades 5.

Within this tubular member 8 is a tubular sleeve 11 threaded in its interior with a coarse pitch thread 12 but Without thread on its exterior as it is freely slidable and revolvable within member 8.

This sleeve extends beyond the spider and end of member 8 to project a distance from the drum and is of somewhat reduced outside diameter from the shoulder 13 and exteriorly threaded with a relatively iine thread at 14, while at the extreme outer end of the sleeve is a collar 15 secured in place by a pin 16.

Within the sleeve 11 and engaging its thread 12 is a threaded bar 17 centrallized at its inner 17 terminates forwardly at l20.. i l

The door or closurezo'f the mixing cylinder is a round 'disk 21 .ribbedas at` 22r and'providedwith a hub 23 loosely supported on the reduced outervend of sleeve 11 and resiliently `forced outward thereon bya shortbut heavyspiral-spring 24, while threadedly mounted I.on the 4iinely threaded por--l tion 14 of the sleeve is a; hub 25 'of a handWheel 26, the arrangementbeing suchthat whenthe handwheel'is screwed vto thel left onsleeve 1 (as seen-.in Fig. 1) "toforcefclosure disk 21 to close the opening in the drumor cylinder 1 byseatingat its outer margin against annularrflange 3 there will be azspace at 27 betweenvtheouter cndvof the handwheel-hub 25,and1thefcollar 15. ,f 1

With this arrangement, and assumingfit is desiredito open the closureplate from the. position shownin Fig. t1,the:handwheel is screwed to the rightin this zfigure and-will merely releaseor crack the opening..of;therclosure by the action;

of spring 24 until the hub 25 engages collar 15 and after which the sleeve 11 will be revolved to quickly unscrew the same on its coarse thread 12 to thus carry the disk clear out to dotted position 21 so that the contents of the drum 1 may be freely discharged. 4

Upon reverse screwing of the handweel the closure disk is rst carried along with a rapid motion on sleeve 11 by reason of the coarse thread 12 until it seats against ilange 3 and after which the resistance transfers the load to iine thread 14 so that the handwheel may make a turn or two thereon to force disk 21 into closer contact with flange 3 while compressing spring 24 slightly and thus seal the closure under the power of the finer thread. The arrangement thus combines the quick travel of the coarse thread and the power of the fine thread in a very simple rugged structure.

The special curved blades 5 are so arranged that when the drum is revolved in direction of the arrow of Fig. 2 they scoop up the material to carry it inwardly toward the center of the drum and urge it over the widening funnel-like arrangement for ejection from the opening when the closure plate 21 is open.

Also within the drum are several plain spirally disposed blades 28 arranged to lift and screw the material generally toward the discharge end of the vdrum for picking up by blades 5.

From the above description it will be seen that a cylindrical drum may be quickly discharged of wet concrete or other material through a cenaxially inward from said opening, means supporting said member from the drum, an interiorly threaded sleeve slidable Within said member and extending outward therefrom, a closure'- disk lfor said opening supported on the outer end of said Y sleeve, a threaded rod within said sleeve threadedly engaging the same and secured at its inner end to said tubular member, and means on the outer end of said sleeve outward vof said'disk adapted for the manual turning of the sleeve. I

2. A horizontally disposed revolvable drum provided with an axially arranged opening at one end, a tubular member within the drum extending axially inward from s'aid opening, means supporting said member from the drum, an interiorly threaded `sleeve slidable within said member and extending outward therefrom, a closure disk for said opening supported on the outer end of said sleeve, a threaded rod within said sleeve threadedly engaging the vsame and secured at its inner end to said tubular member, a handwheel threaded on said sleeve at a' point outward of said disk, a stop on the sleeve beyond said handwheel, and a spring on` said sleeve resiliently forcing said disk toward said handwheel. n

3. In a structure asl specified in claim 2, the threads within the sleeve engaging said rod being coarse relative to the handwheel threads.

` 4. In a structure asspecied in claim 2, said sleeve being of reduced diameter for supporting said disk, and said spring reacting between said disk and the shoulder formed by the reduced diameter of the sleeve. .i

gagement of the disk and seat, said secondary screw means being arranged and adapted for application of greater power than the first mentioned screw means. y

6. A mixer v'drum provided with an end opening, a seat around said opening, a closure disk adapted to cover said opening and to engage said seat for sealing the opening, a manually operated screw means arranged for moving said disk outwardly of the drum into and out of engagement with said seat, secondary screw means varranged and adapted to force the disk tightly against said seat upon engagement of the disk and seat, said secondary screw means being of a finer pitch than the rst mentioned screw means for application of greater power for seating the disk upon actuation thereof.

7. A mixer drum provided with an end opening, a seat around said opening, a closure disk adapted to cover said opening and to engage said seat for sealing the opening, means extending axially of the opening and disk and supporting the latter for movement to and from the seat, manually operated means for moving said disk in the directions stated, and means actuated by engagement of the disk and seat for increasing the power applied to the disk upon further actuation of said manually operated means in the manner for moving the disk toward said seat.

ALFRED E. MASON. 

